Body Composition Changes in Bulls from Weaning to Yearling Part I — Muscle, Waste Fat and Taste Fat Deposition

  • Gene H. Rouse (Iowa State University)
  • Doyle E. Wilson (Iowa State University)
  • Richard G. Tait (Iowa State University)
  • Mike Anderson (Iowa State University)
  • Abebe T. Hassen (Iowa State University)


These results suggest how muscle, subcutaneous fat and intramuscular fat are deposited from weaning to yearling. How might these results be explained?

  • Tissue maturity —muscle matures earlier than fat in the growth process and has nutrient priority over fat when muscle is making maximum growth. Cattle normally make maximum growth, rate/day, when muscle is being deposited at the maximum rate. Why? Muscle has a much higher water content than fat, therefore, it requires less nutrients to deposit a pound of muscle then a pound of fat.
  • 10-1 Concept—during the fattening process, 10 pounds of waste fat (subcutaneous, seam and internal fat) is deposited for each pound of taste fat, (intramuscular fat). This concept may partially explain why waste fat reaches maximum deposition after most of the muscle has been deposited and taste fat is more dependent on age than weight. There may be enough energy available for taste fat to keep ticking along each day—determined by the genetic potential for intramuscular fat.

Developing EPDs for these three independent traits: rib eye area, subcutaneous fat and intramuscular fat allows all segments of the industry to develop functional cattle and by “managing fat” fit unique consumer driven carcass targets.

Keywords: Animal Science, ASL R1822

How to Cite:

Rouse, G. H., Wilson, D. E., Tait, R. G., Anderson, M. & Hassen, A. T., (2004) “Body Composition Changes in Bulls from Weaning to Yearling Part I — Muscle, Waste Fat and Taste Fat Deposition”, Iowa State University Animal Industry Report 1(1).

Download pdf



Published on
01 Jan 2004
Peer Reviewed